Benchmark: Transform: Object.fromEntries vs reduce (10000 entries)

Script Preparation code:

var ENTRIES = 10000;
var data = Array.from(Array(ENTRIES).keys()).map(key => ({id: key, someProp: key + 1}))
var createObject = (value) => ({ id: value.id });

Tests:

Object.fromEntries (with transform data)
Object.fromEntries( data.map( currentObj => { const transformedObj = createObject( currentObj ); return [ transformedObj.id, transformedObj ]; }));
Reduce (reuse object)
data.reduce( ( acc, currentObj ) => { const transformedObj = createObject( currentObj ); acc[ transformedObj.id ] = transformedObj; return acc; }, {});
Reduce (creating temporary objects)
data.reduce( ( acc, currentObj ) => { const transformedObj = createObject( currentObj ); return { ...acc, [ transformedObj.id ]: transformedObj }; }, {} );

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.fromEntries (with transform data)
Reduce (reuse object)
Reduce (creating temporary objects)

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and considered.

**Benchmark Definition:**
The benchmark measures the performance of two approaches for transforming an array of objects into an object using JavaScript:

1. `Object.fromEntries`: Creates an object from an array of key-value pairs.
2. Two variants of the `reduce` method:
	* "Reduce (reuse object)": Reuses the same object to accumulate the transformed data.
	* "Reduce (creating temporary objects)": Creates a new object for each iteration of the reduce method.

**Script Preparation Code:**
The script prepares an array of 10,000 objects with an ID and a property. The `createObject` function is used to transform these objects into their desired form.

```javascript
var ENTRIES = 10000;
var data = Array.from(Array(ENTRIES).keys()).map(key => ({id: key, someProp: key + 1}));
var createObject = (value) => ({ id: value.id });
```

**Html Preparation Code:**
There is no HTML preparation code provided.

**Test Cases:**

1. **"Object.fromEntries (with transform data)":**
	* Benchmark Definition: `Object.fromEntries(data.map(currentObj => { const transformedObj = createObject(currentObj); return [transformedObj.id, transformedObj]; }));`
	* This test case uses the `Object.fromEntries` method with a transformation function to convert each object in the array into an object.
2. **"Reduce (reuse object)":**
	* Benchmark Definition: `data.reduce((acc, currentObj) => { const transformedObj = createObject(currentObj); acc[transformedObj.id] = transformedObj; return acc; }, {});`
	* This test case uses the `reduce` method to accumulate the transformed data into an object. It reuses the same object for each iteration.
3. **"Reduce (creating temporary objects)":**
	* Benchmark Definition: `data.reduce((acc, currentObj) => { const transformedObj = createObject(currentObj); return { ...acc, [transformedObj.id]: transformedObj }; }, {} );`
	* This test case uses the `reduce` method to accumulate the transformed data into an object. It creates a new temporary object for each iteration.

**Pros and Cons:**

1. **`Object.fromEntries`**:
	* Pros:
		+ More concise and readable.
		+ Can be faster due to its internal implementation.
	* Cons:
		+ May have performance issues with large datasets or specific transformation functions.
2. **"Reduce (reuse object)":**
	* Pros:
		+ Can be faster for small datasets due to reduced object creation.
	* Cons:
		+ May lead to increased memory usage and slower performance for large datasets.
3. **"Reduce (creating temporary objects)":**
	* Pros:
		+ Avoids potential issues with reusing objects, ensuring more predictable performance.
	* Cons:
		+ Can be slower due to object creation.

**Library/ Framework Consideration:**
There is no specific library or framework mentioned in the benchmark definition. However, `Object.fromEntries` is a built-in JavaScript method.

**Special JS Features/Syntax:**
None of the test cases explicitly use special JavaScript features or syntax.

**Alternatives:**

1. **Other `reduce` methods**: There may be other variations of the `reduce` method that could be used to accumulate data, such as using `Array.prototype.reduce()` instead of the built-in `reduce()` method.
2. **Alternative transformation functions**: Other transformation functions, such as using `Array.prototype.map()` or a custom function, could be used in place of `Object.fromEntries` or the `createObject` function.

Keep in mind that these alternatives may not necessarily affect the performance results, but they could change the readability and maintainability of the code.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser/OS: Chrome 119 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.fromEntries (with transform data)	1382.6 Ops/sec
Reduce (reuse object)	2513.4 Ops/sec
Reduce (creating temporary objects)	87.0 Ops/sec

Related benchmarks:

Transform: Object.fromEntries vs reduce (10000 entries) (version: 0)

Comparing performance of: Object.fromEntries (with transform data) vs Reduce (reuse object) vs Reduce (creating temporary objects)

Created: one year ago by: Guest

Jump to the latest result

Object.fromEntries (with transform data)

Reduce (reuse object)

Reduce (creating temporary objects)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):